The refrigeration systems essentially comprise a compressor, a condenser and an evaporator, connected to each other through tubular connections, which contain a working fluid that is defined by a refrigerant fluid pumped by the compressor, to promote heat exchange with an ambient usually associated with the evaporator of the refrigeration system.
Among the characteristics responsible for improving the performance of the refrigeration compressors are the increase of the amount of refrigerant fluid, in gas form, drawn during suction, and the reduction of the power necessary to compress this gas, requiring the gas to be under as low temperature as possible (greater specific mass). One of the ways for attaining this object is to use a direct suction system.
In some known compressor constructions for a refrigeration system, the gas suction occurs by direct suction, from an inlet suction tube 1a mounted in the casing 1 of the compressor, to the interior of a suction chamber, usually comprising a suction acoustic muffler 2 disposed in the interior of said casing 1. The suction chamber further comprises a suction orifice generally defined in a valve plate and, in some constructions, an additional suction chamber, defined in a head mounted against the valve plate, both not illustrated. In other known compressor constructions for a refrigeration system, the gas suction occurs by direct suction, but with a suction acoustic muffler 2 mounted outside the casing 1 of the compressor.
In the constructions presenting the suction acoustic muffler 2 inside the casing 1 of the compressor, the tubular connection that defines a suction line of the refrigeration system is maintained in fluid communication with said suction acoustic muffler 2 through a flexible tubular connecting element 3 that provides a hermetic connection between the gas inlet region in the interior of the casing 1 of the compressor, through the inlet suction tube 1a and the suction chamber, accommodating the movements resulting from the relative vibration between said suction chamber and the wall of the casing 1 of the compressor, directing the cold gas of the suction directly to the interior of the suction chamber, minimizing heat exchanges of this cold gas with the gas present in the interior of the casing 1.
The tubular connecting element 3 establishes a passageway for the refrigerant fluid in gas form, being attached, by one of its ends, to the outer part of a gas inlet duct of the suction chamber, usually mounted in the interior of the casing 1 of the compressor (FIG. 1) and having an opposite end seated and pressed against an adjacent inner wall portion of the casing 1, said opposite end surrounding concentrically the inlet suction tube 1a. 
During the start of the compressor or during the normal operation thereof, the pressure inside the tubular connecting element 3 is lower than the pressure outside it, due to the suction effected by the movement of a piston 4, reciprocating inside a cylinder 5 of the compressor, and whose movement draws the refrigerant fluid, in gas form, to the interior of a compression chamber 5a defined inside said cylinder 5, in which is mounted the piston 4. This pressure reduction causes a contraction in the tubular connecting element 3 pulling the whole mechanical assembly of the compressor that is connected to the suction chamber against the wall of the casing 1 of the compressor. The inertia of the mechanical assembly generates a force which tends to oppose to this movement, causing the release of the tubular connecting element 3 from the suction chamber.
In a known solution, the tubular connecting element 3 is constructed in a flexible material with low thermal conductivity which can be retained to the suction acoustic muffler 2 and in sliding contact with the casing 1 of the compressor, as it occurs in the solution described in document U.S. Pat. No. 4,793,775. However, this construction presents the disadvantage, in some conditions, mainly at the start of the compressor, of conducting the tubular connecting element 3 to detach from its mounting condition to the acoustic muffler 2.
In order to guarantee the fixation of the tubular connecting element 3, by its connecting end, to the suction chamber or, more specifically, to the acoustic muffler, it is necessary to install a clamp 6, which externally and radially presses the tubular connecting element 3 against the outer surface of a tubular element 7 of the acoustic muffler 2. This clamp 6 of known construction is manufactured in steel, which generates potential problems related to the safety of the compressor, due to the possibility of this component falling inside the casing 1, causing the risk of a short circuit between the electrically powered parts and the casing 1. Besides, this known construction presents disadvantages as to the mounting of the metallic clamp 6 around the tubular connecting element 3, mainly in situations in which there is not enough space for using tools or automatic mounting devices to be applied to elements that will definitively lock the clamp in the mounted condition.
Another disadvantage of this construction refers to the manufacturing costs of said clamp 6, which by the fact of being metallic, requires cutting and mechanical shaping steps to be manufactured, as well as surface and heat treatments, which also raise the cost of its production.